Hand tool for metal engraving



Jan. v8., 1946; 4 P. vrroux 2,392,560.

HAND TooL FOR METAL ENGBAVING Filed Jan. 15, 1594s i i i-lx Patented Jan. 8, 1946 2,392,5604 y HAND 'rooL Fon METAL ENGRAVING Pierre Vitoux, Troyes, France; vested in the Alien Property Custodian Application January 15, 1943, serial No. 472,535

' In France August 6, `194:1

11 Claims. (Cl. 7S-13.1)

This invention relates to a hand tool for point engraving on metal, or any other hard surfaced material adapted more particularly, inter alia, for tracing names and addresses on identity plates, stamp plates for bicycles, etc.

This tool presents the advantages of being very handy, owing to its simple construction, its convenient weight and its reduced size, while permitting to obtain rapidly and easily a. Very sharp eliglaVlIlg,

These advantages are achieved owing to the fact that While the engraving needle has a small stroke, it nevertheless strikes the plate to be engraved with ra substantial force due to the feature consisting in that said engraving needle is actuated by percussion, by means of percussing members driven by pulses of air under pressure produced by an air machine.,

Several embodiments of such a tool willv be hereinafter described, being schematically shown in the accompanying drawing in which:

Fig. 1 is an elevation of a first embodiment of the tool, of which: v

Fig. 2 is a diametralvertical section and,

Fig. 3 is a detail;

Fig. 4 is a diametral vertical section of-a second embodiment of said tool; and

Fig. 5 is a side elevation of a machine .for generating the air pulses used for drivingthe .percussing members acting on the engraving needle.V

According to the drawing and referring Yto the first embodiment (Figs. 1 to 3), I is a metal cylinder forming the handle adapted to be held pencil-like in the ngers ofv theengraver, 2 being a protecting threaded tip which `permits theV operator to extend the fingers as near as possible to the end of the engraving needle 3, thus `facilitating the handling of the tool. The needle 3 is mounted, in any suitable manner, in a chuck 4, for example, at vthe fend of a sliding rod 5, to which a forward motion is imparted in the cylinder I under the indirect control of the air pulses generated by the air machine, and whose return is effected through the action of a. return spring 6 coiled round the saidrod 5 and housed therewith in the cylinder I. -The reciprocating' motion of said stem 5 is limited, on thel one hand, at its lower end protruding from the cylinder, by-the collar 4' of chuck member 4, said collar and chuck being mounted by a screw thread or otherwise on said stem (this permitting, if necessary, to adjustthe stroke of the needle 3) and on the other hand, the reciprocating motion is limited by a collar 'I l iiexible diaphragm at its upper end, which also protrudes from said cylinder I.

The `upper end of the handle I is topped by a metal cup t, which is integral or integrally connected therewith, the inner circular edge of said cup being rounded. Said cup is 4covered and closed by a cover 9, whose inner circular edgeis also rounded, thesetwoparts being held with their edges in. abutting relation by a threaded gland I0 and formingy the head of the tool, the inner space of which forms a chamber I I receiv-v ing the air pulses controlled and percussion driving members.

The Vdriving members comprise, primar-lima i2, preferably of rubber, peripherally clamped between edges of the cup 8 and the cover 9, said diaphragm dividing the chamber II in two independent compartments.

Said diaphragm is vibrated underthe successive compressive and exhaustive actions produced by the air machine, which actions are transmitted to the upper portion of chamber IIV by a flexible pipe I3 leading to a nipple I4 provided on the cover 9. In order to secure a uni-vr form motion of said diaphragm Whatever the starting position of the air machine may be, an air leak is provided, consisting in an adjustable air flow varying opening I5 in the cover 9, other openings I6 being similarly provided through the wall of thecup 8, in the lower compartment, as well as through the handle I, in View of preventing any back-pressure acting on the diaphragm, due to air contained in said compartment or handle.

For driving the engraving needle 3 by percussion, two washer-like weights I1 are securedto thev center portion and on either side of the vibrating diaphragm I2, said weights being connected together by meansv of a central screw I8"r passing through said diaphragm, which is thus clamped and strengthened. Y'

The diaphragm I2 is flexed towards the bottom of the cup 8 as each air pui is transmitted from the machine, thus causing the weight assembly Il to strike'the end of the rod 5 projecting into said cup, and this striking action,in turn, causes the engraving needle 3, to be projected from the tip 2. The downward or forward stroke of the members 3, 4 and 5 is limited by collar l, whereas the upward 'or return stroke is limited by co1- lar 4,said return stroke being effected by return spring 6. n

In view of securing agood working of the tool, it is essential that-the stroke of the diaphragm' I2 be greater than that of the rod 5 (preferably kby an amountof the order of one tenth of a millimeter). For adjusting the amount' of air flowing through the opening I a screw I9 having a slotted stem 29 (Fig. 3) may be more or less screwed into said opening.

The air machine may be preferably of the type shown in Fig. 5, being specially adapted to actuate the engraving tool by means of air pulses.V

This machine comprises a base 2I supporting an electric motor 22, the shaft 23 of `which drives, through an eccentric or crank assembly 24, the crank rod 25 of a diaphragm pump 26 arranged in'a socket of the base.

The embodiment according to Fig. 4 aims at simplifying the construction of the tool, makingthe same more sturdy and safer and at rthe same time more powerful in operation, as Well as reducing the cost.

I is the metal cylinder with its protecting threaded tip` 2, in which the engraving needle 3 is Vslidably guided and adapted to reciprocate.. The upper end of the cylinder I is screwed into the bottom of the metal cup 21 and the latterl is closed by its .cover 28, these two parts forming the tool head. The inner space of said head constitutes a chamber 29 receiving the members by means of which the engraving needle is .actuated by percussion under the control of compressed air pulses,l `the tightness. of said chamber being secured by .means of .a plastic packing 30 and a packing glandjL/I'his head is also provided with the threaded opening I5, partly closed by the screw I 9 with slotted stem 20, in order to adjust the amount of air passing therethrough, and said head is also provided with openings I6 through thewalls of the cup 21 and the cylinder I forpreventing any back-pressure acting on the I piston32 due to air contained' fin ,the chamber and the handle. l The member operated by pulses-of compressed air and -in turn, effecting ther` drive bypercussion is simply constituted by a sturdy free piston 32 sliding -in .the .chamber l29 and provided WithV cir-- cular slots, or grooves v33, for limiting thel air losses, -a cushioning and returningspring 34 being' inserted between the upper face of said piston 32. and lt-he cover 28. The engraving needle 3 is drive-nthrcugh the medium of an independent.

rod 35, saidred slidingv in the cylinder I between the piston and the upper part or head 3670i the engraving needle 3. Said head 36-15 .adapted to be. reci-procated in a socketv 31 provided in the 'tip'2, the heightof which limits the stroke of said head. A spring 38 constantly urges rearwardly the head 36 of theneedle 3'so as to bring f it-into contact with the rod 351, which isv thus itself brought back towards the piston The stroke. of the piston 32 may begadiustecl by screwing more or less the cylinder vI in the cup bottom 21, the adjusted position thus :obtained being secured by means of a lock nut 33.

The operation of this improved `engraving tool is substantially the same as that. ofthe constructionshown in Figs. l to 3. At each pui-r or pulse Vof .compressed air arriving from vthe air machine,

the hammer-piston 32- strikesv the end-of the inde-l Y ioning memberv for dampingthe impact'o the` A fingers of the` operator,l a'rod co-axially guided in Y piston 32 against the cover 28 and as a rebound member for returning said piston.

Variations, improvements or additions as well as the use of equivalent means may obviously be embodied in the foregoing structural details without departing from the spirit of the invention.

I claim:

1 'An engraving hand tool comprising an air container forming the head of the tool and Vhav-V ing at one end an air inlet adapted to receive air pulses, a percussive member extending throughf out the whole transversal area of said container and adapted to be imparted a vibrating motion along the axis of said container by said pulses acting on that side of said member nearest to Ysaid* end of container having the air inlet, a cylinder extending from said container, said cylinder having a bore therein communicating with the side of said member remote from said air inlet end, said cylinder forming a handle adapted to be held pencil-like in the lingers of the operator, a rod slidably mounted in saidY cylinder bore and having one end thereof protruding into said container to a vpoint within impact range of said vibrating percussive member, an engraving needle slidably mounted in and protruding from the end of said cylinder remote'frorn said head, Y

said needle being adapted to eiect pointy engraving under the action of said impacts transrmitted thereto through the medium o-f said rod, stop means on said cylinder, a second stop means on the needle cooperating with said first. stop means whereby the projection or said needle from the cylinder is limited, and spring means for .returning said percussive member to al normal intermediate position in said ,container and for damping the motion of the percussive member at each end of its stroke..

2. An engraving hand tool comprising an air container forming the. head o f the tool and having at'one .end an air inlet` adapted tov receive air pulses,rsaid container consisting of a cup-shaped body part and a hood-shaped cover part held. together with' their edges in abutting relation by a threaded clamping sleeve screwed on one of said parts and having a flange engaging with the other part, a percussive member extending throughout the whole transversaliarea of said container and adapted to be imparted a vibrating motion along the .axis of said'container byl said pulses acting on that side of said member nearest to the air inlet-end of said container, said percussive member ccmprisingva flexible diaphragm peripherally clamped between the two parts fof said container, Weightsy secured to the center portions andon either side. of said diaphragm, a cylinder co-axial with sai-d containerpone end of said cylinder communicating with that endy of the container opposite. to-the air inlet end, said cylinder forming a handle adaptedftobe held pencil-like in the said cylinder and having one Vend protruding into said; container to a'point Within impact range of said. vibratmg percussive I nember,A an engravingv needle. slidably mounted and. protruding from the end of said cylinder remote. trom the head.

said needle being adapted to.- eftect point engravi ing under the action or said impacts transmitted thereto through the medium of said rod, stopi means of the needle, a second stop means on said cyiinder cooperating withsaid first. stop means whereby the projection of. said .needle from-the cylinder is limited, and s pringmeans for returningsaid percussive-member to. anormal lfmtermediate position in said container and rerY air pulses, a percussive member extending .throughout the whole transversal area of said container and adapted to be imparted a vibrating lmotion along the axis of said container by said pulses acting on that side kof said member nearestto said air inlet end of container, said percussive member comprising a. free piston acting as ja hammer and adapted to slide in said container, said piston being provided with peripheral grooves for limiting the air losses, a cylinder coaxial with said container, said cylinder having a bore `therein communicating with th'e end of said container remote from the air inlet end, said cylinder forming a handle adapted to be held pencil-like in the lingers of the operator, a rod coaxially guided in said cylinder bore with one end thereof protruding into said container to a point within impact range of said vibrating percusy sive member, an engraving needle slidably mounted in and protruding fromthe end of said cylinder remote from the head, said needle being adapted to effect point engraving under the action of said impacts transmitted thereto through the medium of said rod, stop means on the needle, a second stop means on the cylinder throughout the `whole transversal area of lsaid container and adapted to be imparted a vibrating motion along the axis of said container by said pulses acting on that side of said member nearest to said end of container having the air inlet, a cylinder co-axial with said container, said cylinder having a bore therein communicating with the end of said container remote from the air vinlet end, said cylinder forming a handle adapted to be held pencil-like in the fingers of the operator, a rod co-axially guided in said cylinder and having one end protruding into said container to a point within the range of said vibrating percussive member, an engraving needle slidably mounted in and protruding from the end of said cylinder remote from the head, said l needle being adapted to effect point engraving out the whole transversal area of said container l and adapted to ybe imparted a vibrating motion along the axis of said container by said pulses acting on that side of said member nearest to said air inlet end of container, said percussive member comprising a free piston acting as a hammer and adapted to slide in said container, said piston being provided with peripheral grooves for limiting the air losses, a hollow cylinder co-axial with said container, said cylinder hollow communicating with that end of the container opposite to th'e air inlet and, said cylinder forming a handle adapted to be held pencil-like in the fingers of the operator, a rod co-axially guided in the hollow of said cylinder with one end thereof protruding into said container to a point within impact range of said Vibrating percussive member, an extension carried by said cylinder, an engraving needle slidf ably mounted in said extension and protruding therefrom, said extension being provided with a socket and said needle being provided with an enlarged head portion movable in said socket under the action of said rod to eiect point engraving, the height of said socket limiting the stroke of said engraving needle, and spring means for returning said percussive member to a normal intermediate position in said container a-nd for damping the motion of the percussive member at each end of its stroke.

5. An engraving hand tool comprising an air container forming the head of the tool and having at one end an air inlet adapted to receive air pulses, said container having an adjustable air leak opening, a, percussive member extending under the A action of said impacts transmitted thereto through the medium of said rod, stop means on the needle, a second stop on said cylinder co-operating with said first stop means whereby the projection of said needle from the cylinder is limited, and spring means for returning said percussive member to a normalintermediate position in said container and for damping the motion of the percussive member at each end of its stroke. Y

6. An engraving hand tool comprising an air container forming the head of the tool and having at one end an air'inlet adapted to receive air pulses, a percussive member extending throughout the whole transversal area 'of said container and adapted to be imparted a vibrating motion4 along the axis of said container by said pulses acting on that side of said member nearest to said air inlet end of container, said percussive member comprising a free piston acting as a hammer and adapted to slide in said container, said piston being provided with peripheral grooves for limiting the air losses, a cylinder co-axial with said container, said cylinder having a bore therein communicating With the end of said container remote from the air inlet end, said cylinder forming a, handle adapted to be held pencil-like in the fingers of the operator, a rod co-axially guided in said cylinder with one end thereof protruding into 'said container, to a point within impact range of said vibrating percussive member, an

engraving needle slidably mounted in and protruding from the end of said cylinder remote from the head, said needle being adapted to effect point engraving under the actionof said impacts transmitted thereto through the medium of said rod, stop means on the needle, a second stop on the cylinder co-operating with said first stop means whereby the projection of said needle from the cylinder is limited, and spring means for returning said percussive member to a normal intermediate position in said container and for dampingthe motion of the percussive member at each end of its stroke, said spring means including a compression spring inserted between the air inlet end of said container and the side of the percussive piston acted upon by the air pulses.

7. An engraving hand tool comprising an air container `forming the head of the tool and having at one end an air inlet adapted to receive air pulses, a percussive member extending throughout the whole transversal area of said container and adapted to be imparted a vibratingmotion along the axis of said container by said pulses acting on that side of said member nearest to said air inlet end of container, said percussive member comprising a free piston acting as a hammer and adapted to slide in said container, said piston being provided With peripheral rgrooves for limiting the air losses, la cylinder feo-axial With said container, said cylinder having a bore therein communicating with 'the end of Said container remote from the air inlet end, said cylinder formg ing ahandle adapted to be held pencil-like :in

the ngers ofthe operator, arod co-aXially guided in vsaid cylinder and having one end thereo'r' protruding into 'said container to a point Within the range of said vibratingpercussive member, an

extension carried by said cylinder, an engraving Y needle slidably mounted in Ysaid extension and protruding therefrom, said extension being provided With `a socket "and said needle being provided with 'an enlarged head portion movable in said socket under the action of saidrod to effect point engraving, the height of said socket limiting the stroke of saidengraving needle, and spring means for returning said percussive member to a 4normal intermediate position in said container and for damping the motion of the percussive mem..

ber at veach end of its stroke, said spring means including a compression Vspring inserted between the air end of said container and the side of the percussive piston acted upon bythe air pulses and also including another compression .spring inserted in the extension part socket under the head portion of the engraving needle.

8`. An engraving hand tool -comprising an air container forming the head of the tool and having at one end an air inlet adapted to .receive air pulses, a percussive member extending throughout the Whole transversal area of said container and adapted to be imparted a vibrating motion along the axis of said container by said pulses accesso rod co-a'xially guided-in said cylinder bore, and having oneend thereof protruding into said ccnta-iner, to a point Within the range of said vibrating percussive member, an engraving needle slid- -ably mounted in and protruding from the end 'of large air cylinder, va percussive member Vmounted for back and forth movement Within the cylinder and dividing the cylinder into two compartments, a relatively small tubular 'member-extending from said air cylinder, said tubular member having a bore therein communicating with one of said compartments, an axially reciprocable rod mounted acting on that side of said member nearest to y in said bore and having one end thereof projecting into said container to a point within 'impact range of said percussive member, and an engrav- Y Y side of said percussive member from said rod, said inlet valve including a longitudinally slottedrstem threadably secured in a bore leading vfrom said remote compartment.

[PIERRE vrroUX. 

